The type of equipment used to transport circus tigers, environmental factors experienced during transport, and resultant body temperatures of tigers transported were surveyed during hot and cold weather conditions with six different circus tiger acts. Dataloggers recorded interior and exterior temperatures, relative humidity, and radiant heat at 5-min intervals during each trip. Microdataloggers fed to the tigers recorded body temperature and were recovered from eight Bengal (Panthera tigris tigris), Siberian (P. t. altaica), or Bengal–Sumatran (P. t. tigris–P. t. sumatrae) cross tigers from four different circuses. Three basic types of systems were used by circus acts to transport tigers: freestanding cages mounted on wheels that were winched or pushed into a semitrailer for transport, cages built into the trailer itself, and weather-resistant units transported on flatbed railcars or flatbed truck trailers. The highest temperature encountered inside a trailer was 37.3°C in hot weather conditions, but overall, temperatures were usually between 21.1–26.7°C. Temperature inside the trailers did not appear to be affected by movement and did not generally exceed ambient temperatures, indicating adequate insulation and passive ventilation. During cold weather trips, the lowest temperature inside the trailers was −1.1°C, occurring during an overnight stop. Interior temperatures during cold weather transport stayed 2–6°C warmer than ambient temperatures. The body temperatures of the tigers were unaffected by extreme temperatures. The only changes observed in body temperature were increases of 1–2°C caused by activity and excitement associated with loading in several groups of tigers, regardless of whether it was hot or cold weather. Whenever measured, carbon monoxide and ammonia were below the detectable concentrations of 10 and 1 ppm, respectively. Overall, transport did not appear to have any adverse effects on the tigers' ability to thermoregulate.